Oral rehydration solution safely used in breast-fed children without additional water

Sixty-four children of age 3 months to 2 years were treated for diarrhoea in a rural treatment centre with oral rehydration solution (90 mmol/l Na⁺); plain water was not supplied during rehydration. All children continued breastfeeding during the therapy. Serum sodium levels after 24 h of intake indicated that 61 children had serum sodium level below 148 mmol/l and three were above (range 150-151). None of the children developed clinical signs of symptoms of hypernatremia. The use of additional water may not be necessary during rehydration therapy of breast-fed children.